Illumination system

ABSTRACT

An illumination system includes a light source device configured by an excitation light source, a light guiding member and a wavelength converter that are connected in order, and an operation check device. The system further includes: a connector configured to directly and physically connect the operation check device to a light signal emitting end which includes the wavelength converter; a detector configured to detect a light signal emitted from the light signal emitting end when the light signal emitting end and the operation check device are connected by the connector; and an operation determiner configured to determine the operations of the excitation light source, the light guiding member, and the wavelength converter by a detection result in the detector.

CROSS-REFERENCE TO RELATED APPLICATIONS

This is a Continuation Application of PCT Application No.PCT/JP2012/057359, filed Mar. 22, 2012, which was published under PCTArticle 21(2) in Japanese.

This application is based upon and claims the benefit of priority fromprior Japanese Patent Applications No. 2011-066714 and NO. 2011-066715,both filed Mar. 24, 2011, the entire contents of which are incorporatedherein by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to an illumination system whichilluminates an object to be illuminated.

2. Description of the Related Art

For example, in Jpn. Pat. Appln. KOKAI Publication No. 2008-26698, thereis disclosed a light emitting device which is a light source devicehaving a constitution capable of detecting disconnection with highaccuracy. This light source device includes a light source having asemiconductor light emitting element to emit light (for example,excitation light), a lens which condenses the light emitted from thesemiconductor light emitting element, a connector on which the light iscondensed by the lens, a light guiding member connected to theconnector, and an optical part disposed at a tip of the light guidingmember. The light guiding member guides the light condensed on theconnector. An example of the light guiding member is an optical fiber.The light is guided to the optical part by the light guiding member.

Moreover, the above light source device further includes a lightbranching member, which is interposed between the lens and theconnector, to branch the reflected light returned from the optical part,and a light receiving element which receives the reflected lightbranched by the light branching member. The light receiving element isalso a detecting section which detects the reflected light to detect thepresence/absence of a failure of the light source device, for example,the disconnection of the light guiding member.

Jpn. Pat. Appln. KOKAI Publication No. 2008-26698 described above uses aconstitution which detects reflected light branched by a light branchingmember to detect a failure such as disconnection of a light guidingmember. However, detection items to be detected by such reflected lightare limited, and when the measurement items are increased for thepurpose of precisely detecting the failure, it is necessary to mountdetectors on a light source device, which brings about an increase inthe size of the device.

BRIEF SUMMARY OF THE INVENTION

The present invention has been developed in view of the above respects,and an object thereof is to provide an illumination system which candetect a failure of the light source device without increasing the sizeof the light source device.

According to an aspect of the invention, there is provided anillumination system comprising:

a light source device including an excitation light source configured toemit excitation light, a light guiding member configured to guide theexcitation light emitted from the excitation light source, and awavelength converter configured to convert the excitation light guidedby the light guiding member to illumination light having a desiredwavelength and emitting the illumination light to an object to beilluminated, wherein the excitation light source, the light guidingmember and the wavelength converter are connected in order;

an operation check device configured to check a normal operation of thelight source device;

a connector configured to directly and physically connect the operationcheck device to a light signal emitting end which includes thewavelength converter in the light source device;

a detector configured to detect at least one of a light signal emittedfrom the light signal emitting end and heat generation in the lightsignal emitting end when the light signal emitting end and the operationcheck device are connected by the connector; and

an operation determiner configured to determine the operations of theexcitation light source, the light guiding member, and the wavelengthconverter by a detection result in the detector.

According to the present invention, it is possible to provide anillumination system capable of determining the operations of anexcitation light source, a light guiding member, and a wavelengthconverter, that is, capable of detecting a failure in a light sourcedevice, without the increase of the light source device in size.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING

The accompanying drawings, which are incorporated in and constitute apart of the specification, illustrate embodiments of the invention, andtogether with the general description given above and the detaileddescription of the embodiments given below, serve to explain theprinciples of the invention.

FIG. 1 is a block diagram showing the overall configuration of anillumination system according to a first embodiment of the presentinvention;

FIG. 2A is a sectional view showing a configuration example of awavelength conversion unit and an operation check device in theillumination system according to the first embodiment;

FIG. 2B is a sectional view showing the wavelength conversion unit andthe operation check device in FIG. 2A that are connected to each other;

FIG. 3 is a sectional view showing another configuration example of theoperation check device according to the first embodiment;

FIG. 4 is a diagram mainly showing a configuration example of adetermination circuit in the illumination system according to the firstembodiment;

FIG. 5 is a diagram showing another configuration example of thedetermination circuit according to the first embodiment;

FIG. 6A is a perspective view of a light signal emitting end in anillumination system according to a second embodiment of the presentinvention;

FIG. 6B is a diagram illustrating a configuration example of awavelength conversion unit and an operation check device in theillumination system according to the second embodiment;

FIG. 7 is a diagram illustrating a configuration example of an operationcheck device according to a third embodiment of the present invention;

FIG. 8A is a graph showing an example of a distribution spread ascompared with a detected light amount distribution found from a designvalue of the operation check device in FIG. 7;

FIG. 8B is a graph showing an example of a distribution having itscenter shifted relative to the detected light amount distribution foundfrom the design value;

FIG. 9 is a diagram illustrating a configuration example of a wavelengthconversion unit and an operation check device in an illumination systemaccording to a fourth embodiment of the present invention;

FIG. 10 is a diagram illustrating a configuration example of awavelength conversion unit and an operation check device in anillumination system according to a fifth embodiment of the presentinvention;

FIG. 11 is a diagram illustrating a configuration example of anillumination system according to a sixth embodiment of the presentinvention;

FIG. 12 is a diagram illustrating another configuration example of awavelength conversion unit and an operation check device in theillumination system according to the sixth embodiment;

FIG. 13 is a diagram illustrating a configuration example of anillumination system according to an eighth embodiment of the presentinvention;

FIG. 14 is a block diagram showing the overall configuration of anillumination system according to a ninth embodiment of the presentinvention;

FIG. 15A is a sectional view showing a configuration example of awavelength conversion unit and an operation check device in theillumination system according to the ninth embodiment;

FIG. 15B is a sectional view showing the wavelength conversion unit andthe operation check device in FIG. 15A that are connected to each other;

FIG. 16 is a graph illustrating how to find a calorific value from atemperature change;

FIG. 17 is a diagram illustrating a configuration example of awavelength conversion unit and an operation check device in anillumination system according to a tenth embodiment of the presentinvention;

FIG. 18 is a diagram illustrating a configuration example of anoperation check device in an illumination system according to aneleventh embodiment of the present invention;

FIG. 19A is a graph showing an example of a distribution spread ascompared with a detected temperature distribution found from a designvalue of the operation check device in FIG. 18;

FIG. 19B is a graph showing an example of a distribution having itscenter shifted relative to the detected temperature distribution foundfrom the design value;

FIG. 20 is a diagram illustrating a configuration example of awavelength conversion unit and an operation check device in anillumination system according to a twelfth embodiment of the presentinvention; and

FIG. 21 is a diagram illustrating a configuration example of awavelength conversion unit and an operation check device in anillumination system according to a thirteenth embodiment of the presentinvention.

DETAILED DESCRIPTION OF THE INVENTION

Hereinafter, embodiments of the present invention will be described indetail with reference to the drawings.

[First Embodiment]

As shown in FIG. 1, an illumination system 10 according to the firstembodiment of the present invention includes a light source device 12and an operation check device 14. The light source device 12 illuminatesan object to be illuminated by illumination light generated fromexcitation light. The operation check device 14 is connectable to orremovable from the light source device 12. When the operation checkdevice 14 is connected to the light source device 12 and the lightsource device 12 emits a light signal O, the operation check device 14is used to check the state of the light source device 12, i.e., whetherthe light source device 12 fails, in accordance with the state of theemitted light signal O.

The light source device 12 is configured by an excitation light source16, an optical fiber 18, and a wavelength conversion unit 20 that areconnected in order. Here, the excitation light source 16 emitsexcitation light. The optical fiber 18 is a light guiding member whichguides the excitation light emitted from the excitation light source 16.The wavelength conversion unit 20 is a wavelength converter whichconverts the excitation light guided by the optical fiber 18 toillumination light having a desired wavelength and emits theillumination light to the object to be illuminated. The light sourcedevice 12 further includes a light source controller 22 and a display24. Here, the light source controller 22 controls theactivation/deactivation and optical output of the excitation lightsource 16. The display 24 displays various information regarding thelight source device 12.

Each component is described below in detail.

The excitation light source 16 is, for example, a laser device.

The wavelength conversion unit 20 includes a wavelength conversionmember for wavelength conversion, for example, a fluorescent material.The excitation light emitted by the optical fiber 18 is applied to thefluorescent material. The fluorescent material converts the appliedexcitation light to fluorescence having a predetermined wavelengthdifferent from the wavelength of the excitation light. The fluorescencewhich is light having the predetermined wavelength is emitted from thewavelength conversion unit 20 as illumination light for illuminating theobject to be illuminated. Actually, the fluorescent material does nottotally convert the applied excitation light to fluorescence, but partlyconverts the excitation light to fluorescence. Thus, the wavelengthconversion unit 20 emits not only the fluorescence but also theexcitation light. Therefore, the wavelength conversion unit 20 actuallyemits the light signal O including the fluorescence which is theillumination light, and the excitation light which is not converted tofluorescence by the fluorescent material.

On the other hand, the operation check device 14 is removable from alight signal emitting end of the light source device 12 where thewavelength conversion unit 20 is located. The operation check device 14has a connection detector 26 and a light amount sensor 28. Here, theconnection detector 26 detects whether the operation check device 14 isconnected in a proper positional relationship when the operation checkdevice 14 is connected to the light signal emitting end. The lightamount sensor 28 is a detector which detects the light signal O emittedfrom the wavelength conversion unit 20 when the operation check device14 is connected to the light signal emitting end.

The light source controller 22 of the light source device 12 isconfigured to receive a connection detection signal CD from theconnection detector 26 of the operation check device 14, and a detectedlight amount DO from the light amount sensor 28. The light sourcecontroller 22 includes a determination circuit 30 which is an operationdetermination circuit to determine whether the light source device 12fails, i.e., determine the operations of the excitation light source 16,the optical fiber 18, and the wavelength conversion unit 20, inaccordance with the detected light amount DO from the light amountsensor 28. The failure in the light source device 12 means, for example,the breaking of the optical fiber 18, and the leakage of the excitationlight caused by the breaking of the optical fiber. Otherwise, thefailure in the light source device 12 means, for example, thedeterioration of emission efficiency of the excitation light orfluorescence caused by the breakdown of the wavelength conversion unit20, and an unnecessary increase of the excitation light. Thedetermination of whether the light source device 12 fails is describedlater.

In the illumination system 10 having the configuration described above,the operation check device 14 is used to determine the operation of thelight source device 12 before the light source device 12 illuminates theobject to be illuminated.

For example, this operation determination is automatically performed atleast at the time of the application of electric power to the lightsource device 12 or after operational initialization of the light sourcedevice 12. In this operation determination, before the activation of theexcitation light source 16, the light source controller 22 firstascertains in accordance with the connection detection signal CD fromthe connection detector 26 that the operation check device 14 isconnected to the light signal emitting end of the wavelength conversionunit 20 of the light source device 12 in a proper positionalrelationship. After the connection is ascertained, the light sourcecontroller 22 activates the excitation light source 16 to emit the lightsignal O from the wavelength conversion unit 20. Using the detectedlight amount DO which is emitted light information detected by the lightamount sensor 28 of the operation check device 14, the determinationcircuit 30 then determines the state of the light source device 12. Inaccordance with the determination, the light source controller 22controls the optical output of the light signal O. That is, when thelight source device 12 is determined to be dangerous or improper foractivation, the light emission by the excitation light source 16 isinhibited, or the amount of the excitation light is limited. If theoperation check device 14 is disconnected from the light signal emittingend, the light signal O under optical output control is emitted from thelight signal emitting end. The determination result or, the controlresult of the optical output of the light signal O may be displayed onthe display 24.

Now, specific configurations of the wavelength conversion unit 20 of thelight source device 12 and the operation check device 14 are described.

As shown in FIG. 2A and FIG. 2B, the light source device 12 has a lightsignal emitting end 32 for holding the optical fiber 18 and thewavelength conversion unit 20. The wavelength conversion unit 20 islocated at the tip of the optical fiber 18 in the light signal emittingend 32. The wavelength conversion unit 20 has a fluorescent material 34and a tapered mirror 36. Here, the fluorescent material 34 is awavelength conversion member which converts the wavelength of theexcitation light emitted through the optical fiber 18. The taperedmirror 36 is located in the rear of the fluorescent material 34 (on theside of the optical fiber 18). As described above, the light signal Oincluding fluorescence which is the illumination light converted by thefluorescent material 34 and the excitation light which is not convertedto fluorescence by the fluorescent material is emitted from an emissionopening 38 provided at the tip of the light signal emitting end 32. Thetapered mirror 36 is disposed to emit, from the emission opening 38,light traveling in directions other than the direction of the emissionopening 38 out of the fluorescence converted by the fluorescent material34. It should be appreciated that the wavelength conversion unit 20 isnot limited to the structure described here and has only to be astructure that uses the fluorescent material 34.

The operation check device 14 is removable from the light signalemitting end 32, and includes the connection detector 26 and the lightamount sensor 28. The operation check device 14 further includes aconnector 40 and a light blocking cover 42. Here, the connector 40directly and physically connects the light signal emitting end 32 andthe operation check device 14. The light blocking cover 42 is a lightblocking component which blocks, when connected, the light signal Oemitted from the light signal emitting end 32.

The light amount sensor 28 is disposed on the inner surface of a concavein the light blocking cover 42, and is located to be in front of theemission opening 38 of the wavelength conversion unit 20. The connector40 is provided with a projection 44 for alignment to keep a givendistance between the light amount sensor 28 and the emission opening 38.

As shown in FIG. 2B, when the operation check device 14 is attached tothe light signal emitting end 32 of the wavelength conversion unit 20,the emission opening 38 is covered with the light blocking cover 42.Therefore, the light emitted from the emission opening 38 does not leakout, and the light emitted from the emission opening 38 only enters thelight amount sensor 28, so that the influence of external light can beeliminated. As the optical output is not yet controlled at the time ofthe operation determination of the light source device 12, a dangerouslevel of light may be emitted from the emission opening 38. However,such light, even if emitted, does not cause damage to, for example, aperson outside because the emission opening 38 is covered with the lightblocking cover 42.

The connection detector 26 detects whether the light blocking cover 42and the light amount sensor 28 fixed thereto are placed at properpositions. The connection detector 26 may be configured to optically orelectromagnetically detect access, or may be configured to electricallydetect connection by the contact of electrodes.

A wavelength filter 46 which transmits the excitation light is providedin front of the light amount sensor 28 (on the side of the emissionopening 38). Thus, when the operation check device 14 is connected tothe light signal emitting end 32 and the excitation light source 16emits excitation light, the light amount sensor 28 detects the state ofthe excitation light in a situation where the wavelength conversion unit20 emits fluorescence and the excitation light. If the wavelengthconversion unit 20 breaks down, the excitation light converted tofluorescence by the wavelength conversion unit 20 decreases, and theexcitation light emitted as excitation light from the emission opening38 increases. Therefore, the breakdown of the wavelength conversion unit20 decreases the emission of fluorescence and increases the emission ofexcitation light. The excitation light has a high risk of causing damagewhen directly applied to human eyes or skin. Thus, the amount ofexcitation light is detected here. For example, if the optical fiber 18has broken or deteriorated, the excitation light leaks out of the brokenor deteriorated part, so that the amount of excitation light enteringthe wavelength conversion unit 20 decreases, and the amount ofexcitation light penetrating the wavelength conversion unit 20 alsodecreases.

As shown in FIG. 3, an excitation light amount detector and afluorescence amount detector may be configured by providing two lightamount sensors 28 and disposing wavelength filters 46E and 46F whichrespectively transmit excitation light and fluorescence so that theamount of excitation light and the amount of fluorescence can beindependently detected. That is, a small failure in the light sourcedevice 12 that is not shown in the change of the amount of excitationlight may be detected as the change of the amount of fluorescence. Thus,the detection of the amount of fluorescence is meaningful.

Alternatively, a spectrometric detector may be used instead of thewavelength filter 46 and the light amount sensor 28. When such aspectrometric detector is used, the determination circuit 30 may onlydetermine in accordance with the amount of the excitation lightwavelength detected by the spectrometric detector, or may determine inaccordance with relative intensity between the amount of the excitationlight wavelength and the amount of the fluorescence wavelength.

As shown in FIG. 4, for example, the determination circuit 30 of thelight source device 12 can be configured by a comparator 48 whichcompares a detected light amount DO from the light amount sensor 28 ofthe operation check device 14 with a reference voltage REF correspondingto a predetermined value. The output of the comparator 48 will be adetermination result DR by the determination circuit 30. Thisdetermination circuit 30 determines whether the amount of excitationlight is less than or equal to the predetermined value, and therebydetermines whether the light source device 12 fails, i.e., determinesthe operations of the excitation light source 16, the optical fiber 18,and the wavelength conversion unit 20.

Alternatively, for example, as shown in FIG. 5, the determinationcircuit 30 of the light source device 12 may include two comparators 50and 52 and an AND operator 54. Here, the comparator 50 compares thedetected light amount DO from the light amount sensor 28 of theoperation check device 14 with a reference voltage REF1 corresponding toa lower limit value within a predetermined range. The comparator 52compares the detected light amount DO from the light amount sensor 28with a reference voltage REF2 corresponding to an upper limit valuewithin the predetermined range. The AND operator 54 takes an AND of thedetermination results by the comparators 50 and 52. The output of theAND operator 54 will be the final determination result DR of thedetermination circuit 30. This determination circuit 30 determineswhether the amount of excitation light is within a predetermined range,and thereby determines whether the light source device 12 fails, i.e.,determines the operations of the excitation light source 16, the opticalfiber 18, and the wavelength conversion unit 20.

Here, the determination circuit 30 determines by one of the followingmethods:

-   -   (1) The determination circuit 30 determines that the operation        is “proper” when the amount of the excitation light output to        the outside through the wavelength conversion unit 20 is within        the range of a light amount found in consideration of production        variance of the excitation light source 16 and the wavelength        conversion unit 20, or the determination circuit 30 determines        that the operation is “improper” when the amount of the        excitation light is not within the light amount range;    -   (2) The determination circuit 30 determines that the operation        is “proper” when it is expected from the amount of excitation        light in consideration of the deterioration of the wavelength        conversion unit 20 that there is enough time before future        deterioration and danger, or the determination circuit 30        determines that the operation is “improper” when it is expected        that there is not enough time; and    -   (3) The determination circuit 30 determines that it is        “dangerous” when the wavelength conversion unit 20 breaks down        and the amount of the excitation light output from the emission        opening 38 of the wavelength conversion unit 20 influences other        devices or the human body, or the determination circuit 30        determines that it is “safe” when the light amount has no        influence.

For example, when the excitation light source 16 is a laser device asdescribed above, excitation light which is laser light greater than orequal to the predetermined value may be emitted from the emissionopening 38 if the light source device 12 fails. If the excitation lightgreater than or equal to the predetermined value is emitted, the usermay be affected, and desired safety may not be maintained, or otherdevices may be affected. Thus, the determination circuit 30 determinesthat it is “safe” if the detected amount of excitation light is lessthan or equal to the predetermined value, or the determination circuit30 determines that it is “dangerous” if the detected amount ofexcitation light is more than the predetermined value. The predeterminedvalue which is the threshold of this determination can be based on, forexample, the light amount detected by the light amount sensor 28 whenthe amount of the excitation light that influences other devices or theuser of the light source device 12 is emitted. The threshold of thisdetermination may be based on laser safety classes defined by, forexample, international standards.

The failure in the light source device 12 means, for example, thebreakdown of the wavelength conversion unit 20. If the wavelengthconversion unit 20 breaks down, the excitation light converted tofluorescence by the wavelength conversion unit 20 decreases, and theexcitation light emitted as excitation light from the emission opening38 increases. Therefore, the breakdown of the wavelength conversion unit20 decreases the emission of fluorescence and increases the emission ofexcitation light.

The “proper” operation and “improper” operation are decided, forexample, by whether the excitation light source 16 and the wavelengthconversion unit 20 can satisfy designed specifications, or by whetherthere is enough time before the wavelength conversion unit 20 becomesdangerous as a result of its deterioration in consideration of thedeterioration of the wavelength conversion unit 20. The predeterminedvalue which is the threshold of this determination can be found, forexample, in consideration of production variance of the excitation lightsource 16 and the wavelength conversion unit 20 so that the excitationlight source 16 and the wavelength conversion unit 20 satisfy thedesigned specifications. The predetermined value is lower than thepredetermined value in the case of “safe” and “dangerous”.

The determination circuit 30 obtains a determination result bypreviously setting, in the comparator 48 or the comparators 50 and 52,the reference voltage REF corresponding to the predetermined value forone of the case of “safe” and “dangerous” and the case of “proper” and“improper”. It should be appreciated that the amount of excitation light(the optical output of the excitation light source 16) may be controlledin accordance with the combination of the determinations “safe” and“dangerous” and the determinations “proper” and “improper”.

Although the determination is based on the amount of excitation light inthe example described here, it is also possible to determine by theamount of fluorescence or by both the amounts of excitation light andfluorescence. Alternatively, it is also possible to use thespectrometric detector to determine by deriving the amount of excitationlight and the amount of fluorescence from a spectrum. It is alsopossible to determine by the ratio between the amount of excitationlight and the amount of fluorescence.

After the operation check device 14 is removed from the light sourcedevice 12 by user operation, the light source controller 22 controls theoptical output of the excitation light source 16 in accordance with theprevious determination result. When it is determined to be “safe” or theoperation is determined to be “proper”, the illumination light can beoutput. When it is determined to be “dangerous” or the operation isdetermined to be “improper”, the excitation light source 16 is stopped,or the amount of excitation light is limited.

According to the illumination system 10 in the first embodimentdescribed above, the light amount sensor provided in the operation checkdevice 14 receives the light signal O when the operation check device 14is connected to the light signal emitting end 32. It is thereby possibleto determine the operations of the excitation light source 16, theoptical fiber 18, and the wavelength conversion unit 20 in accordancewith the detected light signal O, i.e., detect the failure in the lightsource device 12. Thus, in the present embodiment, the breakdown of theoptical fiber 18 and the wavelength conversion unit 20 can be opticallydetected without the addition of new components to the optical system ofthe light source device 12, so that the increase of the light sourcedevice 12 in size can be prevented.

According to the present embodiment, the operation check device 14 hasonly to be connected to the light signal emitting end 32. The breakdownof the optical fiber 18 and the wavelength conversion unit 20 isoptically detected by the configuration with a high degree of freedom indesigning without the addition of new components to the optical systemof the light source device 12. It is possible to inhibit any dangerousoperation of the light source device 12 in the event of the detection ofthe breakdown. When no breakdown is detected and the light source device12 is put into operation, the operation check device 14 is removed andtherefore does not affect the operation and usability of the lightsource device 12.

According to the present embodiment, a determination is based on anoptical detection result, which leads to a shorter time for thedetermination of a failure in the light source device 12 and to highresponse. Moreover, influence resulting from the failure is directlydetected, which permits reliable detection.

[Second Embodiment]

In an illumination system 10 according to the second embodiment, aplurality of wavelength conversion units 20 are disposed in an lightsignal emitting end 32 of a light source device 12.

For example, in the example shown in FIG. 6A, three wavelengthconversion units 20 are disposed in the light signal emitting end 32,and the light signal emitting end 32 includes three emission openings38. Regarding the guiding of light to each of the wavelength conversionunits 20, excitation light emitted from the excitation light source 16may be branched and guided to the wavelength conversion units 20 by aplurality of optical fibers 18. Alternatively, excitation light emittedfrom the excitation light source 16 may be guided into the light signalemitting end 32 by one optical fiber 18, and branched to the wavelengthconversion units 20 in the light signal emitting end 32.

In the configuration in which a plurality of wavelength conversion units20 are disposed in the light signal emitting end 32 of the light sourcedevice 12, a cutout 56 is provided in the outer periphery of the lightsignal emitting end 32, and a protrusion 58 to be fitted into the cutout56 is provided in the inner periphery of a light blocking cover 42 of anoperation check device 14, as shown in FIG. 6A and FIG. 6B. A lightamount sensor 28 is located to face each of the wavelength conversionunits 20 when the operation check device 14 is connected to the lightsignal emitting end 32 to fit the protrusion 58 into the cutout 56. Thisensures that the light amount of each of the wavelength conversion units20 can be detected. When a plurality of wavelength conversion units 20are provided in this way, a connector 40 preferably has a connectionstructure that uniquely decides a positional relationship between thelight amount sensor 28 and the light signal emitting end 32.

[Third Embodiment]

As shown in FIG. 7, an illumination system 10 according to the thirdembodiment is equipped with a two-dimensional array light amount sensor60 capable of light amount distribution measurement instead of theabove-mentioned light amount sensor 28. A two-dimensional PD or animaging element can be used as the two-dimensional array light amountsensor 60.

In this case, a determination circuit 30 determines that it is “safe” orthe operation is “proper” if a light distribution characteristic (thedistribution of a light amount DO) measured by the two-dimensional arraylight amount sensor 60 is located between a predetermined upper limitvalue U and a lower limit value L as compared with a distributionobtained from a design value. On the contrary, when a distributionspreads as shown in FIG. 8A as compared with the distribution obtainedfrom the design value or when the center of the distribution is shiftedas shown in FIG. 8B, the determination circuit 30 determines that it is“dangerous” or the operation is “improper”.

If a color filter is provided instead of a wavelength filter 46, it ispossible to use a configuration which determines by the distribution ofeach wavelength (each color). In this case, it is possible to determineby the respective distributions of excitation light and fluorescence.

The determination time can be reduced by finding a maximum light amountfrom the detection value of the measured light amount distribution anddetermining by this value rather than by comparing the detection valueof the light amount distribution measured by the two-dimensional arraylight amount sensor 60 with the distribution obtained from the designvalue.

[Fourth Embodiment]

As shown in FIG. 9, in an illumination system 10 according to the fourthembodiment, a scattering plate 62 is disposed inside a light blockingcover 42 of an operation check device 14, and a light amount sensor 28is located in the place where a light signal O emitted from an emissionopening 38 of a wavelength conversion unit 20 does not enter directly.

In this configuration, the light signal O emitted from the emissionopening 38 is applied to the scattering plate 62, and reflected andscattered by the scattering plate 62 in various directions.

Therefore, even when the light signal O has a light distribution, thelight signal O can be averaged and thus detected by the light amountsensor 28. Therefore, even when the light amount sensor 28 is notlocated in front of the emission opening 38 of the wavelength conversionunit 20, the status of the whole light signal O can be detected if thelight amount sensor 28 is located to be able to measure the light amountof the light signal O scattered by the scattering plate 62.

In the second embodiment in which a plurality of wavelength conversionunits 20 are disposed in the light signal emitting end 32 of the lightsource device 12, one light amount sensor 28 alone may be used as in theconfiguration according to the present embodiment instead of a pluralityof light amount sensors 28. In this configuration, reflected andscattered light of the light signal O emitted by each of the wavelengthconversion units 20 enters the light amount sensor 28. This ensures thatthe light amount of each of the wavelength conversion units 20 can bedetected.

[Fifth Embodiment]

As shown in FIG. 10, in an illumination system 10 according to the fifthembodiment, a light amount sensor 28 is not provided in an operationcheck device 14 but provided in a light signal emitting end 32 of alight source device 12. In this case, the operation check device 14 hasa scattering plate 62 disposed inside a light blocking cover 42, as inthe fourth embodiment.

In this configuration, a light signal O emitted from an emission opening38 of a wavelength conversion unit 20 is reflected and scattered by thescattering plate 62 in the light blocking cover 42, and then enters thelight amount sensor 28 provided in the light signal emitting end 32.

If the light source device 12 has an observation function, the lightamount sensor 28 does not need to be additionally provided, and animaging element that constitutes the observation function may be usedfor light amount detection. An imaging element with a color filter canseparately detect excitation light and fluorescence, and can also detecta light distribution.

Although a connection detector 26 is located not in the operation checkdevice 14 but in the light signal emitting end 32 of the light sourcedevice 12 in FIG. 10, the operation is similar to that when theconnection detector 26 located in the operation check device 14. Itshould be appreciated that the connection detector 26 may also belocated in the light signal emitting end 32 in the configurationsaccording to the first to fourth embodiments. Conversely, it should beappreciated that the connection detector 26 may be located in theoperation check device 14 in the present embodiment as well.

[Sixth Embodiment]

As shown in FIG. 11, an illumination system 10 according to the sixthembodiment transmits information from the operation check device 14 tothe light source device 12 by wireless communication WC using atransmitter 64 which is an infrared, electromagnetic coupling, or radiowave wireless transmitter and a receiver 66 which is a wirelessreceiver.

In this case, a determination circuit 30 disposed in a light sourcecontroller 22 may be disposed between a light amount sensor 28 of theoperation check device 14 and the transmitter 64. In this arrangement, adetermination result has only to be transmitted as the contents of awireless communication, so that a communication system can be simpler.

If a connection detector 26 is also disposed in a light signal emittingend 32 of the light source device 12, wired connection to the operationcheck device 14 can be eliminated.

As shown in FIG. 12, the receiver 66 may be provided at such a positionin the light signal emitting end 32 that the transmitter 64 and thereceiver 66 face each other when the operation check device 14 isconnected to the light signal emitting end 32. In this case, thetransmitter 64 and the receiver 66 can be low-power transmitter andreceiver that are only operable within a short distance so that theoperation check device 14 only operates when properly connected. Thisallows connection detection based on the operations of the transmitter64 and the receiver 66. Consequently, the connection detector 26 canalso be omitted.

The transmitter 64 and the receiver 66 may be a transmitter and areceiver capable of two-way wireless communication so that powertransmitted from the light source device 12 by the transmitter andreceiver is used for the operation in the operation check device 14instead of the provision of a battery in the operation check device 14.

Although the connection detector 26 is disposed in the light signalemitting end 32 in FIG. 11 and FIG. 12, it should be appreciated thatthe connection detector 26 may be disposed in the operation check device14.

[Seventh Embodiment]

An illumination system 10 according to the seventh embodiment uses alight amount sensor 28 as a photoelectric cell.

Thus, a light signal O which is not used for the actual illumination ofan object to be illuminated and which is only used for determination canbe converted to electric power and used for the operation of anoperation check device 14.

[Eighth Embodiment]

As shown in FIG. 13, in an illumination system 10 according to theeighth embodiment, an operation check device 14 is incorporated in alight source device body 68 which has an excitation light source 16 anda light source controller 22 therein.

This can eliminate the work of connecting the operation check device 14and the light source controller 22, and also eliminate the fear of theloss of the operation check device 14.

Although a connection detector 26 is disposed in a light signal emittingend 32 in FIG. 13, the connection detector 26 may be disposed in theoperation check device 14.

[Ninth Embodiment]

As shown in FIG. 14, in an illumination system 10 according to the ninthembodiment of the present invention, an operation check device 14 isprovided with, instead of the above-mentioned light amount sensor 28, atemperature sensor 70 which is a detector for detecting heat generationin a light signal emitting end 32 when the operation check device 14 isconnected to the light signal emitting end 32.

In the present embodiment, a determination circuit 30 in a light sourcecontroller 22 of a light source device 12 determines whether the lightsource device 12 fails, i.e., determines the operations of an excitationlight source 16, an optical fiber 18, and a wavelength conversion unit20 in accordance with a detected temperature DT which is heat generationin the light signal emitting end 32 detected by the temperature sensor70.

Although a connection detector 26 is provided in the light source device12 in FIG. 14, the connection detector 26 may be provided in theoperation check device 14.

Specifically, the operation check device 14 is removable from the lightsignal emitting end 32 as shown in FIG. 15A, and includes thetemperature sensor 70. The temperature sensor 70 is located in theconnector 40 to face the side surface of the light signal emitting end32 of the light source device 12. In particular, the temperature sensor70 is disposed in the place where the heat generation in the wavelengthconversion unit 20 which is the heat generation source in the lightsignal emitting end 32 can be monitored, i.e., in the place where heatis well conducted from the wavelength conversion unit 20. Specifically,the temperature sensor 70 is located on the inner surface of theconnector 40 so that the temperature sensor 70 comes into contact withthe light signal emitting end 32 when the light signal emitting end 32of the light source device 12 is inserted as shown in FIG. 15B. As alight signal O is not applied to the temperature sensor 70 in thisplace, a temperature rise caused by the light signal O can be prevented.Therefore, this place is preferable when a contact temperature sensorsuch as a thermocouple or a thermister is used as the temperature sensor70.

In the present embodiment, a heat insulating material 72 having a lowthermal conductivity is disposed around the temperature sensor 70 and onthe inner surface of the connector 40 where the operation check device14 comes into contact with the light signal emitting end 32 of the lightsource device 12. Thus, the temperature sensor 70 can accurately measurethe temperature of the light signal emitting end 32 of the light sourcedevice 12, i.e., the temperature of the wavelength conversion unit 20without being influenced by the heat generation and thermal diffusion ofthe operation check device 14. The heat insulating material 72 isprovided with a projection 74 for alignment so that the light signalemitting end 32 is held at a position that allows the temperature sensor70 to correctly detect the temperature of the wavelength conversion unit20 in the light signal emitting end 32 when the operation check device14 is connected to the light signal emitting end 32.

The connection detector 26 detects whether the operation check device 14and the temperature sensor 70 fixed thereto are placed at properpositions. The connection detector 26 may be configured to optically orelectromagnetically detect access, or may be configured to electricallydetect connection by the contact of electrodes.

The determination circuit 30 of the light source device 12 can besimilar to that in the first embodiment described above. That is, thedetermination circuit 30 can be configured by a comparator 48 whichcompares the detected temperature DT from the temperature sensor 70 ofthe operation check device 14 with a reference voltage REF correspondingto a predetermined value. The output of the comparator 48 will be adetermination result DR by the determination circuit 30. Thisdetermination circuit 30 determines whether the detected temperature DTis less than or equal to the predetermined value, and thereby determineswhether the light source device 12 fails, i.e., determines theoperations of the excitation light source 16, the optical fiber 18, andthe wavelength conversion unit 20.

Alternatively, for example, the determination circuit 30 of the lightsource device 12 may include an AND operator. The determination circuit30 uses two comparators 50 and 52 to compare the detected temperature DTfrom the temperature sensor 70 of the operation check device 14 withfirst and second reference voltages REF1 and REF2 corresponding to alower limit value and an upper limit value within a predetermined range,and the AND operator calculates an AND of the determination results bythe two comparators 50 and 52 to obtain the final determination resultDR. This determination circuit 30 determines whether the detectedtemperature DT is within a predetermined range, and thereby determineswhether the light source device 12 fails, i.e., determines theoperations of the excitation light source 16, the optical fiber 18, andthe wavelength conversion unit 20.

Here, the determination circuit 30 determines by one of the followingmethods:

-   -   (1) The determination circuit 30 determines that the operation        is “proper” when the heat generation from the wavelength        conversion unit 20 indicated by the detected temperature DT is        within the range of heat generation (temperature range) found in        consideration of production variance of the excitation light        source 16 and the wavelength conversion unit 20, or the        determination circuit 30 determines that the operation is        “improper” when the heat generation is not within the heat        generation range;    -   (2) The determination circuit 30 determines that the operation        is “proper” when it is expected from the detected temperature DT        that there is enough time before future deterioration and        danger, or the determination circuit 30 determines that the        operation is “improper” when it is expected the time is short;    -   (3) The determination circuit 30 determines that the operation        is “proper” when it is predicted from the heat generation from        the wavelength conversion unit 20 indicated by the detected        temperature DT that the wavelength conversion unit 20 is        operating in a condition assumed at the time of designing, or        the determination circuit 30 determines that the operation is        “improper” when the wavelength conversion unit 20 is operating        in a condition that is not assumed. For example, the        determination circuit 30 determines that the operation is        “proper” when the detected temperature DT indicates heat        (temperature) which is generated when the amount of excitation        light penetrating the wavelength conversion unit 20 is within a        designed range, or the determination circuit 30 determines that        the operation is “improper” when the amount of excitation light        is out of the designed range of heat generation;    -   (4) The determination circuit 30 determines that it is        “dangerous” when the detected temperature DT indicates that the        heat generated from the wavelength conversion unit 20 has        brought the light signal emitting end 32 of the light source        device 12 to a temperature that influences other devices or the        user, or the determination circuit 30 determines that it is        “safe” when there is no influence; and    -   (5) The determination circuit 30 determines that it is        “dangerous” when it is predicted from the heat (detected        temperature DT) generated from the wavelength conversion unit 20        that the wavelength conversion unit 20 is operating in a        dangerous condition, or the determination circuit 30 determines        that it is “safe” when it is predicted that the wavelength        conversion unit 20 is operating in a safe condition. For        example, the determination circuit 30 determines that it is        “dangerous” when the excitation light penetrating the wavelength        conversion unit 20 has increased and heat generated by a        dangerous light amount is detected.

The breakdown of the wavelength conversion unit 20, for example, thedeterioration of a fluorescent material 34 deteriorates thetransmittance of the excitation light when penetrating the wavelengthconversion unit 20, and increases the amount of excitation lightabsorbed by the wavelength conversion unit 20. Thus, the calorific valueis higher than in a normal condition in which the fluorescent material34 has not deteriorated, i.e., in which the wavelength conversion unit20 has not broken down. The temperature of the light signal emitting end32 increases accordingly.

In contrast, as a result of the breakdown of the wavelength conversionunit 20 such that the fluorescent material 34 has deviated from theoptical axes of the light source device 12 and the optical fiber 18 andthe excitation light does not enter the fluorescent material 34, theamount of excitation light absorbed by the wavelength conversion unit 20decreases. Consequently, the calorific value is reduced and thetemperature of the light signal emitting end 32 is reduced as comparedwith the normal condition in which the fluorescent material 34 has notcome off the light source device 12, i.e., in which the wavelengthconversion unit 20 has not broken down.

If the optical fiber 18 has broken or deteriorated, the excitation lightleaks out of the broken or deteriorated part, so that the amount ofexcitation light entering the wavelength conversion unit 20 decreases,the calorific value of the wavelength conversion unit 20 decreases.

Thus, when the temperature is out of a predetermined range, otherdevices or the user may be affected by the increase of the amount ofexcitation light leaking from the wavelength conversion unit 20 or theincrease of the amount of excitation light leaking from the opticalfiber 18.

Therefore, the determination circuit 30 determines whether it is “safe”or “dangerous” by whether the temperature of the light signal emittingend 32 detected by the temperature sensor 70 is less than or equal to apredetermined value or is within the predetermined range. Thepredetermined value or the predetermined range has only to be decided bythe influence on the user or other devices, and, for example, can befound in consideration of the temperature of the light signal emittingend 32 resulting from the leakage of the excitation light of thewavelength conversion unit 20. The predetermined value or thepredetermined range may otherwise be decided by a predicted value or by,for example, international standards when the light source device 12 isdesigned.

The “proper” operation and “improper” operation are decided, forexample, by whether the excitation light source 16 and the wavelengthconversion unit 20 can satisfy designed specifications, or by whetherthere is enough time before the wavelength conversion unit 20 becomesdangerous as a result of its deterioration in consideration of thedeterioration of the wavelength conversion unit 20. The predeterminedvalue or the predetermined range which is the threshold of thisdetermination can be found, for example, in consideration of productionvariance of the excitation light source 16 and the wavelength conversionunit 20 so that the excitation light source 16 and the wavelengthconversion unit 20 satisfy the designed specifications. Thepredetermined value or range is lower than the predetermined value orrange in the case of “safe” and “dangerous”.

The determination circuit 30 obtains a determination result bypreviously setting, in the comparator 48 or the comparators 50 and 52,the reference voltage REF corresponding to the predetermined value forone of the case of “safe” and “dangerous” and the case of “proper” and“improper”. It should be appreciated that the amount of excitation light(the optical output of the excitation light source 16) may be controlledin accordance with the combination of the determinations “safe” and“dangerous” and the determinations “proper” and “improper”.

Although the determination is based on the detected temperature DT inthe example described here, a calorific value may be predicted from thedetected temperature DT, and the predicted value may be used fordetermination. In this case, the calorific value can be found by atemperature change and by thermal resistance Rt and thermal capacity Ctof the light signal emitting end 32, as shown in FIG. 16. The thermalresistance is a value ranging from the wavelength conversion unit 20 tothe temperature sensor 70. The thermal capacity is the value of thelight signal emitting end 32. For these values, designed values orexperimental values can be used.

According to the illumination system 10 in the ninth embodimentdescribed above, the temperature sensor 70 provided in the operationcheck device 14 detects the temperature as the heat generation in thelight signal emitting end 32 when the operation check device 14 isconnected to the light signal emitting end 32. It is thereby possible todetermine, in accordance with the detected temperature, the operationsof the excitation light source 16, the optical fiber 18, and thewavelength conversion unit 20, i.e., detect the failure in the lightsource device 12. Thus, in the present embodiment, the breakdown of theoptical fiber 18 and the wavelength conversion unit 20 can be detectedwithout the addition of new components to the optical system of thelight source device 12, so that the increase of the light source device12 in size can be prevented.

According to the present embodiment, the operation check device 14 hasonly to be connected to the light signal emitting end 32. The breakdownof the optical fiber 18 and the wavelength conversion unit 20 isdetected by the configuration with a high degree of freedom in designingwithout the addition of new components to the optical system of thelight source device 12. It is possible to inhibit any dangerousoperation of the light source device 12 in the event of the detection ofthe breakdown. When no breakdown is detected and the light source device12 is put into operation, the operation check device 14 is removed andtherefore does not affect the operation and usability of the lightsource device 12.

According to the present embodiment, the determination is based on thedetected heat generation, so that breakdown can be detected early undercertain conditions. Even if the accuracy of the attachment of theoperation check device 14 is not so high, breakdown can be accuratelyand stably detected. Details of the breakdown (damage) can be analyzedfrom the heat generation, and proper measures can be taken against thebreakdown.

[Tenth Embodiment]

In an illumination system 10 according to the tenth embodiment, as shownin FIG. 17, a noncontact temperature sensor 76 which optically detectstemperature as an infrared temperature sensor is used instead of thecontact temperature sensor 70 in the ninth embodiment described above.This noncontact temperature sensor 76 is preferably disposed on theinner surface of a depression in a light blocking cover 42 where a heatgenerating position can be easily measured. When an operation checkdevice 14 is attached to a light signal emitting end 32, an emissionopening 38 of the light signal emitting end 32 is covered with the lightblocking cover 42. Therefore, light emitted from the emission opening 38does not leak out, and the light emitted from the emission opening 38only enters the noncontact temperature sensor 76, so that the influenceof external light can be eliminated. Even if a dangerous level of lightis emitted from the emission opening 38 during the determination of theoperation of a light source device 12 when the optical output is not yetcontrolled, the light does not cause damage to, for example, a personoutside because the emission opening 38 is covered with the lightblocking cover 42.

An advantage of the present embodiment is that the heat insulatingmaterial 72 in the ninth embodiment described above is unnecessarybecause the heat generation and thermal diffusion of the operation checkdevice 14 resulting from the contact with the light signal emitting end32 do not affect the detection result by the noncontact temperaturesensor 76. However, a connector 40 is provided with a projection 44 foralignment as a connection structure to keep a given distance between thenoncontact temperature sensor 76 and the light signal emitting end 32.

The connection detector 26 may be provided in the light signal emittingend 32 as in the ninth embodiment, or may be provided in the operationcheck device 14 as shown in FIG. 17.

[Eleventh Embodiment]

As shown in FIG. 18, an illumination system 10 according to the eleventhembodiment is equipped with a noncontact two-dimensional arraytemperature sensor 78 capable of measuring a two-dimensionaldistribution of temperature instead of the noncontact temperature sensor76 in the tenth embodiment described above.

In this case, a determination circuit 30 determines that it is “safe” orthe operation is “proper” if a temperature distribution measured by thenoncontact two-dimensional array temperature sensor 78 is locatedbetween a predetermined upper limit value and a lower limit value ascompared with a distribution obtained from a design value. On thecontrary, when a distribution spreads as shown in FIG. 19A as comparedwith the distribution obtained from the design value or when the centerof the distribution is shifted as shown in FIG. 19B, the determinationcircuit 30 determines that it is “dangerous” or the operation is“improper”.

The determination time can be reduced by finding a maximum value fromthe detection value of the measured temperature distribution anddetermining by this maximum value rather than by comparing the detectionvalue of the temperature distribution measured by the noncontacttwo-dimensional array temperature sensor 78 with the distributionobtained from the design value.

In the present embodiment as well, a connection detector 26 may beprovided in a light signal emitting end 32, or may be provided in anoperation check device 14.

[Twelfth Embodiment]

As shown in FIG. 20, in an illumination system 10 according to thetwelfth embodiment, a second temperature sensor 80 is further disposedin a place that is not affected by heat generation in a light signalemitting end 32, in the configuration according to the ninth embodiment.A light source controller 22 determines by the difference between theambient temperature detected by the second temperature sensor 80 and adetected temperature DT shown by a temperature sensor 70 located in thevicinity of a wavelength conversion unit 20.

For example, the second temperature sensor 80 is attached to a region inan operation check device 14 which is out of contact with the lightsignal emitting end 32 and to which the signal light emitted from thelight signal emitting end 32 is not applied. It should be appreciatedthat the second temperature sensor 80 is not limited to this positionand may be attached to, for example, the outer surface of the operationcheck device 14.

A more accurate determination can be made by the use of the differencebetween the ambient temperature and the detected temperature DT.

[Thirteenth Embodiment]

In an illumination system 10 according to the thirteenth embodiment, aplurality of wavelength conversion units 20 are provided in a lightsignal emitting end 32 of a light source device 12.

For example, as in the second embodiment described above, when threewavelength conversion units 20 are disposed in the light signal emittingend 32, a cutout 56 is provided in the outer periphery of the lightsignal emitting end 32, and a protrusion 58 to be fitted into the cutout56 is provided in the inner periphery of a light blocking cover 42 of anoperation check device 14, as shown in FIG. 6A and FIG. 6B. In the samemanner as the light amount sensor 28 according to the second embodimentdescribed above, a temperature sensor 70 is also located to face each ofthe wavelength conversion units 20, as shown in FIG. 21. Thisconfiguration ensures that the temperature of each of the wavelengthconversion units 20 can be detected. When a plurality of wavelengthconversion units 20 are provided in this way, a connector 40 preferablyhas a connection structure that uniquely decides a positionalrelationship between the temperature sensor 70 and the light signalemitting end 32.

A noncontact two-dimensional array temperature sensor 78 capable ofmeasuring a two-dimensional distribution of temperature may be disposedin contact with the outer periphery of the light signal emitting end 32to determine by the maximum temperature that is detected.

While the present invention has been described in connection with theembodiments, it should be understood that the invention is not limitedto the embodiments described above and various modifications andapplications can be made within the spirit of the scope of the presentinvention.

For example, as in the sixth embodiment, the determination circuit 30may be provided not within the light source controller 22 but in theoperation check device 14 in the other embodiments as well.

In the ninth to thirteenth embodiments as well, information may betransmitted from the operation check device 14 to the light sourcedevice 12 by infrared, electromagnetic coupling, or radio wave wirelesscommunication. In this case, the determination circuit 30 which has beendisposed in the light source controller 22 is provided in side of thetemperature sensor 70 of the operation check device 14, and adetermination result is transmitted as the contents of the wirelesscommunication, so that the communication system can be simpler.

The operation check device 14 including a temperature detector such asthe temperature sensor 70 may be incorporated in the light source devicebody 68 which has the excitation light source 16 and the light sourcecontroller 22 therein, as in the eighth embodiment described above.

Both a light signal detector such as the light amount sensor 28 and atemperature detector such as the temperature sensor may be used todetermine the operations of the excitation light source 16, the opticalfiber 18, and the wavelength conversion unit 20, i.e., determine thefailure in the light source device 12.

Additional advantages and modifications will readily occur to thoseskilled in the art. Therefore, the invention in its broader aspects isnot limited to the specific details, and representative devices shownand described herein. Accordingly, various modifications may be madewithout departing from the spirit or scope of the general inventiveconcept as defined by the appended claims and their equivalents.

What is claimed is:
 1. An operation check device for checking anoperation of a light source device, wherein the light source devicecomprises: a light source configured to emit an excitation light; afluorescent material configured to: convert a first portion of theexcitation light to an illumination light; and emit an emitted lightcomprising the illumination light and a second portion of the excitationlight; and a light emitting end defining an emission opening throughwhich the emitted light is emitted to an environment, and wherein theoperation check device comprises: a connector configured to connect tothe light emitting end of the light source device; an emitted lightdetector connected to the connector, wherein the emitted light detectoris configured to: independently detect an amount of the second portionof the excitation light; and independently detect an amount of theillumination light; and a determination circuit configured to: determinea first change of the amount of the second portion of the excitationlight detected by the emitted light detector; determine a second changeof the amount of the illumination light detected by the emitted lightdetector; determine a state of the light source based on the firstchange and the second change; and determine a state of the fluorescentmaterial based on the first change and the second change.
 2. Theoperation check device according to claim 1, further comprising a lightblocking cover connected to the connector, wherein the light blockingcover is configured to block the emitted light emitted from the emissionopening of the light emitting end from the environment.
 3. The operationcheck device according to claim 2, wherein the emitted light detector isdisposed in the light blocking cover.
 4. The operation check deviceaccording to claim 3, wherein the emitted light detector is disposed ata position of the light blocking cover in front of the light emittingend.
 5. The operation check device according to claim 1, wherein theconnector is configured to hold the light emitting end and the emittedlight detector in a predetermined positional relationship.
 6. Theoperation check device according to claim 5, wherein the connectorcomprises a connection structure configured to, when the connector isconnected to the light emitting end, uniquely decide a positionalrelationship between the emitted light detector and the light emittingend.
 7. The operation check device according to claim 5, wherein theconnector comprises a connection structure configured to, when theconnector is connected to the light emitting end, keep a given distancebetween the emitted light detector and the light emitting end.
 8. Theoperation check device according to claim 1, wherein the excitationlight is in a first wavelength range and the illumination light is in asecond wavelength range different from the first wavelength range, andwherein the emitted light detector is a spectrometric detectorconfigured to detect an intensity of the second portion of theexcitation light and to detect an intensity of the illumination light.9. The operation check device according to claim 1, wherein theoperation check device further comprises a wireless transmitterconfigured to wirelessly transmit the state of the light source and thestate of the fluorescent material determined by the determinationcircuit to the outside of the operation check device.
 10. The operationcheck device according to claim 1, wherein the connector is configuredto be removably connected to the light emitting end of the light sourcedevice, and wherein the operation check device further comprises aconnection detector configured to detect a direct and physicalconnection between the light emitting end and the connector, wherein theconnection detector is configured to perform one or more of electricallydetect, optically detect, and electromagnetically detect the direct andphysical connection between the light emitting end and the connector.11. The operation check device according to claim 1, wherein the emittedlight detector is configured to measure a light amount distribution. 12.The operation check device according to claim 1, wherein the emittedlight detector is configured to detect the emitted light scattered bythe optical scattering plate.
 13. The operation check device accordingto claim 1, wherein the connector is configured to be removablyconnected to the light emitting end of the light source device.
 14. Theoperation check device according to claim 1, wherein the light sourcedevice further comprises an optical fiber configured to guide theexcitation light emitted by the light source to the fluorescentmaterial, wherein the determination circuit is further configured todetermine a state of the optical fiber based on the first change and thesecond change.
 15. The operation check device according to claim 1,wherein the determination circuit is configured to: determine the firstchange as a change between the amount of the second portion of theexcitation light detected by the emitted light detector and a firstpredetermined amount; and determine the second change as a changebetween the amount of the illumination light detected by the emittedlight detector and a second predetermined amount.
 16. The operationcheck device according to claim 1, wherein the determination circuit isconfigured to: determine the amount of the second portion of theexcitation light detected by the emitted light detector at a first time;determine the amount of the second portion of the excitation lightdetected by the emitted light detector at a second time after the firsttime; determine the amount of the illumination light detected by theemitted light detector at the first time; determine the amount of theillumination light detected by the emitted light detector at the secondtime; determine the first change as a change between the amount of thesecond portion of the excitation light detected by the emitted lightdetector at the first time and the amount of the second portion of theexcitation light detected by the emitted light detector at the secondtime; and determine the second change as a change between the amount ofthe illumination light detected by the emitted light detector at thefirst time and the amount of the illumination light detected by theemitted light detector at the second time.